Brain Responses to a 6-Hz Binaural Beat: Effects on General Theta Rhythm and Frontal Midline Theta Activity

Abstract

A binaural beat is a beat phenomenon that is generated by the dichotic presentation of two almost equivalent pure tones but with slightly different frequencies. The brain responses to binaural beats remain controversial; therefore, the aim of this study was to investigate theta activity responses to a binaural beat by controlling factors affecting localization, including beat frequency, carrier tone frequency, exposure duration, and recording procedure. Exposure to a 6-Hz binaural beat on a 250 Hz carrier tone for 30 min was utilized in this study. Quantitative electroencephalography (QEEG) was utilized as the recording modality. Twenty-eight participants were divided into experimental and control groups. Emotional states were evaluated by Brunel Mood Scale (BRMUS) before and after exposing to the stimulus. The results showed that theta activity was induced in the entire cortex within 10 min of exposure to the stimulus in the experimental group. Compared to the control group, theta activity was also induced at the frontal and parietal-central regions, which included the Fz position, and left hemisphere dominance was presented for other exposure durations. The pattern recorded for 10 min of exposure appeared to be brain functions of a meditative state. Moreover, tension factor of BRUMS was decreased in experimental group compared to control group which resembled the meditation effect. Thus, a 6-Hz binaural beat on a 250 Hz carrier tone was suggested as a stimulus for inducing a meditative state.

Binaural Beats through the auditory pathway: from brainstem to connectivity patterns

“…Monaural beats elicit higher cortical entrainment at the beat frequency than their binaural counterparts Both beat types entrained the brain at their beat frequencies, with monaural conditions eliciting the highest response when compared to binaural conditions. In terms of Theta beat frequency, both Jirakittayakorn & Wongsawat (2017) and Karino et al (2006), found similar entrainment using Theta binaural beats with exposure times between five and ten minutes. Following Garcia-Argibay's conclusions (2018), relatively long exposure time and non-masked binaural beats (i.e.…”

“…Auditory stimulation at the theta frequency band (4 -7 Hz) has been associated with positive emotional experiences and introspection (Aftanas & Golocheikine, 2001), reduced perceived pain in patients with chronic pain (Zampi, 2015), states of meditation and decreased alertness (Jirakittayakorn & Wongsawat, 2017) and enhancement of immediate verbal memory (Ortiz et al, 2008). Furthermore, theta cortical activity is related to concentration, focused attention and a general meditative state (Takahashi et al, 2005;Lagopoulos et al, 2009).…”

Binaural Beats through the Auditory Pathway: From Brainstem to Connectivity Patterns

“…Auditory stimulation at the u frequency band (4-7 Hz) has been associated with positive emotional experiences and introspection (Aftanas and Golocheikine, 2001), reduced perceived pain in patients with chronic pain (Zampi, 2015), states of meditation and decreased alertness (Jirakittayakorn and Wongsawat, 2017), and enhancement of immediate verbal memory (Ortiz et al, 2008). Furthermore, u cortical activity is related to concentration, focused attention and a general meditative state (Takahashi et al, 2005;Lagopoulos et al, 2009).…”

Quality Assessment for Delta and Theta Binaural Beats

“…The dichotic presentation of two nearly equivalent pure tones with slightly different frequencies lead to what we called 'beat' in the brain. The beat in this case generated within the brain and is referred to as a 'binaural beat' (Jirakittayakorn and Wongsawat, 2017;Chaieb et al, 2015). When a tone of 410 Hz presented to the right ear as an example and a 420 Hz one to the left, then a beat of 10 Hz shall be perceived and located in the brain with carrier frequency of 415 Hz (Chaieb et al, 2015;Anonymous, 2017).…”

“…The researchers by Padmanabhan et al (2005) found that binaural beat audio has the role in decreasing acute pre-operative anxiety affectively. For inducing a meditative state, Jirakittayakorn and Wongsawat (2017) suggested that 6 Hz binaural beat on a 250 Hz carrier tone can be regard as a good stimulus. Mihajloski et al (2014) developed a new procedure of evoking transient auditory evoked potentials to binaural beats by adopting frequency modulated stimuli.…”